Greenland sharks could be longest-living vertebrate ever for as long as 400 years

Scientists recently discovered that Greenland sharks could live for as long as 400 years, making them the longest-living vertebrates on record by a huge margin. The previous record holder was the bowhead whale, which can live up to two centuries.

Greenland sharks (Somniosus microcephalus) are world-renowned scavengers that will eat pretty much anything: whale, squid, fish, even a moose. Compared to other sharks, the Greenland is agonizingly slow, averaging a single mile per hour. It can grow to over 20 feet in length, growth can take centuries.

As reported in the journal Science, researchers led by marine biologist John Steffensen from the University of Copenhagen were able to determine that Greenland sharks —also known as the gurry shark or grey shark — grew only about 1 centimeter per year. The average shark is about 5 meters in length, revealing a growth curve that helped them estimate a Greenland shark’s age based on its size. They also used the unusual method of testing Greenland sharks for "bomb pulses" of carbon-14, a heavy isotope left behind by nuclear bomb testing in the mid-1950s.

The technique of dating Greenland sharks by Steffensen and his team was creative enough to earn praises from his colleagues. "Who would have expected that nuclear bombs [one day] could help to determine the life span of marine sharks?" Michael Oellermann, a cold-water physiologist at Loligo Systems in Viborg, Denmark, told Science.

By correlating radiocarbon dates with shark lengths to calculate the age, the research team discovered one particularly aged shark was 392 years old, give or take 120 years. That would put this shark’s estimated birthday in the year 1624.

These sharks are so old, they don’t even begin mating until they are at least 156 years old, the research team says. That’s a long time to remain abstinent.